Modern vehicles contain numerous electronic and electrical switches. Vehicle features such as climate controls, audio system controls, other electrical systems and the like are now activated, deactivated and adjusted in response to electrical signals generated by various switches in response to driver/passenger inputs, sensor readings and the like. These electrical control signals are typically relayed from the switch to the controlled devices via copper wires or other electrical conductors. Presently, many control applications use a single wire to indicate two discrete states (e.g. ON/OFF, TRUE/FALSE, HIGH/LOW, etc.) using a high or low voltage transmitted on the wire.
To implement more than two states, additional control signals are typically used. In a conventional two/four wheel drive transfer control, for example, four active states of the control (e.g. 2WD mode, auto 4WD mode, 4WD LO mode and 4WD HI mode) as well as a default mode are represented using three to five discrete (two-state) switches coupled to a single or dual-axis control lever. As the lever is actuated, the various switches identify the position of the lever to place the vehicle in the desired mode. Many other types of multi-state switches (e.g. single or multi-pole, momentary, locked position, sliding actuator, rotary actuator and the like) are used in a wide array of applications in automotive, aerospace, military, industrial, consumer and other applications.
As consumers demand additional electronic features in newer vehicles and other products, the amount of wiring used to implement such features continues to increase. This additional wiring frequently occupies valuable space, adds undesirable weight and increases the manufacturing complexity of the vehicle. There is therefore an ongoing need (particularly in vehicle applications) to reduce the amount of wiring in the vehicle without sacrificing features. Further, there is a need to increase the number of states represented by various switches without adding weight, volume or complexity commonly associated with additional wiring, and without sacrificing safety. Still further, there is a demand for switches and switching systems that are capable of reliably selecting between four or more operating states of a controlled device, especially in automotive and other vehicle settings.
In particular, it is desirable to formulate multi-state switching devices that capable of representing four or more operating states without adding excessive cost, complexity or weight. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.